Thanks for the answer.
Where I'm at is trying to find some suitable winter wheels for the winter tires, I'm in Canada, Eh!
What I have a shot at is some aftermarket alloy 18 x 8 wheels with a 20 mm offset and like to think that once in a while I have enough sense to ask for input.
A bit of "look before you leap", I'm tired of the hard landings!
The winter tires are 235/50-18 and have been on the stock rims before, I can't see that there would be much issue with that little bit more of offset, but it never hurts to ask.